88 lines
2.0 KiB
JavaScript
88 lines
2.0 KiB
JavaScript
const lodash = require('lodash')
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/**
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* 找出 newObj 相对于 oldObj 有差异的部分
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*
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* @param oldObj
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* @param newObj
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* @returns {{}|*}
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*/
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function doDiff (oldObj, newObj) {
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if (newObj == null) {
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return oldObj
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}
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// 临时的对象，用于找出被删除的数据
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const tempObj = { ...oldObj }
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// 删除空项，使差异对象更干净一些，体现出用户自定义内容
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deleteNullItems(tempObj)
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// 保存差异的对象
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const diffObj = {}
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// 读取新对象，并解析
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for (const key in newObj) {
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const newValue = newObj[key]
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const oldValue = oldObj[key]
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// 新值不为空，旧值为空时，直接取新值
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if (newValue != null && oldValue == null) {
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diffObj[key] = newValue
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continue
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}
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// 新旧值相等时，忽略
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if (lodash.isEqual(newValue, oldValue)) {
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delete tempObj[key]
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continue
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}
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// 新的值为数组时，直接取新值
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if (lodash.isArray(newValue)) {
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diffObj[key] = newValue
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delete tempObj[key]
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continue
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}
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// 新的值为对象时，递归合并
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if (lodash.isObject(newValue)) {
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diffObj[key] = doDiff(oldValue, newValue)
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delete tempObj[key]
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continue
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}
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// 基础类型，直接覆盖
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delete tempObj[key]
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diffObj[key] = newValue
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}
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// tempObj 里面剩下的是被删掉的数据
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lodash.forEach(tempObj, (oldValue, key) => {
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// 将被删除的属性设置为null，目的是为了merge时，将被删掉的对象设置为null，达到删除的目的
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diffObj[key] = null
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})
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return diffObj
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}
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function deleteNullItems (target) {
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lodash.forEach(target, (item, key) => {
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if (item == null) {
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delete target[key]
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}
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if (lodash.isObject(item)) {
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deleteNullItems(item)
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}
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})
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}
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module.exports = {
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doMerge: function (oldObj, newObj) {
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return lodash.mergeWith(oldObj, newObj, function (objValue, srcValue) {
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if (lodash.isArray(objValue)) {
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return srcValue
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}
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})
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},
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doDiff,
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deleteNullItems
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}
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